Use of the comment package

Question

In a .tex document, I'm using the comment package to produce two different versions (let's say : versionA and versionB) of the document. Each version contains different parts (it could be paragraphs, equations,...). If I use \includecomment{versionA}, it will include all the content between \begin{versionA} and \end{versionA}. Now, let's say some of the parts in each version are marked with a *. How can I ask latex to compile only the * parts in one version ?

It may be clearer on the following example. Let's say I have

\documentclass[10pt,a4paper]{article}

\usepackage{comment}
\includecomment{versionA}
\excludecomment{versionB}

\begin{document}

\begin{versionA}

*part1

part2

*part3

\end{versionA}

\begin{versionB}

part1

*part2

\end{versionB}

\end{document}

I would like something which enables me to do : "compile all the content of versionA" or "compile only the content marked with * in versionA" (same for versionB). I hope this is clear!

Answer 1

This will allow you to get all (and only) the starred parts of your document I have added some indentation in order to highlight the different groups of version):

\documentclass[10pt,a4paper]{article}    
\usepackage{comment}
\includecomment{versionA}
\includecomment{versionB}
\excludecomment{versionC}

\begin{document}

\begin{versionA}
    *part1
    \begin{versionC}
        part2
    \end{versionC}
    *part3
\end{versionA}

\begin{versionB}
    \begin{versionC}
        part1
    \end{versionC}
    *part2
\end{versionB}

\end{document}

This code will allow you to get all the starred parts from the A version (to get the ones from the B version just invert versionA and versionB in the include/excludecomment commands in the preamble):

\documentclass[10pt,a4paper]{article}    
    \usepackage{comment}
    \includecomment{versionA}
    \excludecomment{versionB}
    \excludecomment{versionC}

    \begin{document}

    \begin{versionA}
        *part1
        \begin{versionC}
            part2
        \end{versionC}
        *part3
    \end{versionA}

    \begin{versionB}
        \begin{versionC}
            part1
        \end{versionC}
        *part2
    \end{versionB}

    \end{document}